I just rebuilt my E-10 brake valve on my 102-C3. If you have an e-10 valve, it is common in the world of heavy trucks/buses. You can find a myriad of different brands selling rebuild kits for those. If you're looking for an MCI # you'll have to call them. Mine was a standard Bendix E-10, so no problems finding parts.
The part Bendix part number is 102100 and the instructions can be found online and were also included in the kit that I purchased. It is a very simple process to rebuild those, but bear in mind that there are springs that are under some pressure. A vise will be handy to control the disassembly of certain parts. (The instructions were very clear about that part.)
Your mileage may vary, just my experience.
Durwin
